Vehicle for the automatic laying of a track by a vehicle travelling on said track and track designed for installation by such a vehicle

ABSTRACT

Vehicle able to lay a specially designed track formed from elements (5, 6, 7) joined end to end. The vehicle (8) advances along the track and carries a track element on the carriage. When it reaches the end of the track, the carriage is lowered so that the element can be fitted into the preceding element. The elements are of different types so as to permit track height and direction changes.

This is a division of application Ser. No. 07/979,827, filed Nov. 20,1992, now U.S. Pat. No. 5,331,898.

BACKGROUND OF THE INVENTION

The invention firstly relates to a vehicle for the automatic laying of atrack on which it travels and also to a track designed for installationby such a vehicle.

It is used when it is necessary to carry out work within a contaminatedenclosure or an enclosure which is inaccessible for some other reason.The work has to be carried out by robots, which does not in itself causea problem, provided that they are able to approach their interventionlocation, which is often impossible with conventional vehicles carryingrobots, because the locations can be at very different heights or may besurrounded by obstacles rendering them inaccessible.

SUMMARY OF THE INVENTION

The invention obviates such problems in numerous cases. Its object isthe establishment of a track in space and which can be curved or steppedform so as to be able to theoretically reach any random point within theenclosure. The track is cantilevered as from an embedded end locatedoutside the dangerous area and which serves as a starting base for thetool-carrying robot.

However, it is necessary to be able to lay or construct the trackwithout human intervention. It is for this reason that a vehicle hasbeen designed, which travels on said track and which is continuouslyable to lay new track elements one following the other once it hasreached the end of the already laid track. This vehicle is characterizedin its most general form by a chassis, as well as means for adhering toand travelling on the track, together with a carriage movingperpendicular to the track in the chassis and having means for holding atrack element and placing it in front of the track elements a)readyjoined end to end.

An end of track detection sensor can advantageously be provided on thevehicle, as well as a position sensor of the element held by thecarriage in order to check that it is in the desired longitudinalposition at the time when it has to be laid.

As it is preferable to secure against failure of the end of trackdetection sensors, it is possible to add a track end stopping means, tothe chassis. In accordance with the invention the stopping meanscomprises a lever articulated to the chassis, and having a free mobileend on the track. An opposite end of the lever is articulated to thechassis and provides a step which abuts a wall at the end of the trackwhen the free end projects beyond the end of the track.

The chassis guiding and advancing means includes transverse rollers orpulleys gripping slideways or slide bars of rails provided by the trackelements joined end to end. An identical arrangement is practicable forholding the track elements in the carriage. With such a design, thevehicle is unable to fall from the track no matter what the inclinationof the latter. The track elements previously held by the carriage can bereleased after the track elements have been laid by on advancing thevehicle until the carriage rollers pass out of the rod or slideways.

The vehicle can also be provided with means for modifying the state orthe mobile parts of the track or for locking the elements together. Itcan be in the form of a key member rotating about a spindleperpendicular to the track and which is provided with an end having aflat notch or a flat projection.

The track can comprise a rod on slideway-carrying body in extension onthe elements joined end to end and a rack parallel to the slideways andon which engages a pinion belonging to the track vehicle displacementmeans. The elements can be terminated by couplings having slidingengagement and vertical abutment, such as tapered dovetails. Among otheroptional characteristics which can be used separately or in combination,it is possible to add to the elements one or more stop marks at the endof the elements for the optical or other end of track sensors, or alongitudinal notch terminated by an abutment wall in order to retain theend of track stop means. The direction change means can be provided witha part rotating about an axis perpendicular to the track for bentelements or assume the form of track inclination elements designed, inthe effectively constructed embodiment, in the form of elements having arotary part able to pivot about the axis of the element. The inclinationis ensured by an adjacent bent element and used in combination. Such anarrangement makes it unnecessary to interrupt the rigidity of the track.

The rotary parts are preferably actuated by an irreversible mechanism,having a clearance and friction for reasons which will be describedhereinafter in conjunction with the use of a flat notch or projectingkey member.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in greater detail hereinafter relative tonon-limitative embodiments and with reference to the attached drawings,wherein show:

FIG. 1 A general view of a track produced according to the invention.

FIG. 2 The track starting point.

FIG. 3 Certain special features of the track.

FIGS. 4, 5, and 6 The laying of an element and certain features of thevehicle.

FIGS. 7 and 8 More specifically the locking mode.

FIG. 9 A bent element.

FIGS. 10 and 11 Two sections of the bent element along lines X--X andXI--XI of FIG. 9.

FIG. 12 An inclination element.

FIG. 13 How said element is used.

FIGS. 14 and 15 Two sections of the inclination element along linesXIV--XIV and XV--XV of FIGS. 13 and 12 respectively.

FIGS. 16 In cross-section the nature and use of the mechanism forlocking and actuating the mobile parts.

FIG. 17 A plan view of the locking and actuating mechanism on thevehicle, as well as the end of track stop means.

FIGS. 18 to 20 The stop means in other forms.

FIG. 21 Another type of track with branched elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The track shown in FIGS. 1, 2 and 3 extends within an enclosure 1defining a hostile atmosphere. The enclosure 1 has an opening 2 throughwhich extends the track in order to form, outside said enclosure 1, astarting portion 3 embedded in a support 4 by a weld or bolted joint.The starting portion 3 is used for the introduction of vehicles on thetrack, their removal and the loading of different equipment. Openings ormanipulating means, such as locks and glove boxes, are located on theside of the starting portion 3 and make it possible to perform theseoperations manually.

However, the track essentially extends within the enclosure 1 and isconstituted by elements joined end to end in succession and of whichthree different types occur. Most are in the form of straight elements5, whose section is uniform and whose shape is immutable, bent elements6 making it possible to change track direction and inclination elements7 formed from two parts pivoting with respect to one another about theaxis of the element. Such an inclination element 7 in combination with abent element 6 makes it possible to modify the gradient the track beyondthe same and therefore its height. These elements and specific meansmaking it possible to control them will be described hereinafter. Thestarting portion 3 can be looked upon as a fourth type of track elementused for embedding purposes. A fifth type, which allows branchingactions and which in fact constitutes a switch point, will be describedrelative to FIG. 21.

A vehicle 8 travels on the track or more specifically on a pair ofslideways 9 or parallel bars or rods at the top of the elements 5, 6 and7 constituting the track and which extend on all the rectilinearportions of the track. However, discontinuities are inevitable with thechosen design, i.e. curve-free, with respect to the bent elements 6 andinclination elements 7. The bent elements 6 have a plate 10 rotatingabout a spindle 11 and which extends over most of their height toessentially comprise the slideways 9 of said bent element 6. Therotation of the plates 10 when the vehicle is located on their slideways9 modifies its direction and aligns it with one of the adjacent trackportions.

The vehicle 8 is manually inserted around the slideways 9 by the end ofthe track starting portion 3. It firstly comprises an inert chassis 99,which carries a carriage 12 able to hold a track element 5, 6 or 7 andwhich is vertically movable (or more generally perpendicular to thetrack) with respect to the chassis 99, so as to lower the held trackelement and then raise it again. It consequently constitutes anelevator. It can be seen that if the vehicle 8 is at the end of thealready installed track, the held element could be placed in extensionof the preceding element and assembled therewith by a dovetail coupling13 at the end of all the elements 5, 6 and 7. Thus the track isconstructed element by element. Once the carriage 12 has returned to itsinitial position and the vehicle 8 has passed out of the enclosure 1, anew element can be loaded onto the carriage 12 and the vehicle 8 willlay it so as to further extend the track.

FIG. 4 is a more detailed view of the vehicle 8 and the track in thedirection of FIG. 2 and shows that the vehicle 8 slides on the track bymeans of two pairs of rollers or pulleys 14 having a central groove andwhich are located on either side of the slideways 9. Thus, each pair ofrollers 14 grips around the slideways 9. Thus, no track inclination canpull the vehicle 8 off the track. A motor 15 drives a pinion 16, whichengages in a rack 17 belonging to the elements 5, 6 and 7 and parallelto the slideways 9 in order to advance the vehicle 8 on the track. Thecarriage 12 holds the element to be laid at the end of the track withthe aid of two other pairs of rollers or pulleys 18, similar to those ofthe vehicle 8, but only one roller 18 is visible here. One of therollers 14 or 18 of each pair rotates about a fixed spindle and theother about a spindle located at the end of a lever articulated at afixed point and rotating in the plane of the slideways 9. The lever ispushed back by a spring towards the slideways 9, which are consequentlygripped between each pair of rollers 14 or 18. Moreover, the spacing ofthe rollers 14 or 18 or each pair is automatically regulated so as toadjust it to the shape and position variations which may effect theslideways 9.

Reference should now be made to FIGS. 5 and 6. The vehicle 8 is opentowards the front and rear to give a passage for the held track element.The carriage 12 comprises vertical profiles having a U-shaped section19, which slide in posts 20 serving as vertical slideways for the twosides of the vehicle 8. A vertical rack 21 is also located on one of thesides of the vehicle 8 and a pinion 22 actuated by a motor 24 located onthe carriage 12 makes it possible to lower or raise the same asrequired. When the previously held track element has been laid, thecarriage 12 is freed by advancing it on the track until its rollers 18pass out or the slideways 9.

A pinion 26 then engages with the rack 17 of the element held by thecarriage 12 and makes it possible for the held element to advance inorder to bring it in front or the preceding element when the vehicle 8remains stationary after reaching the end of the track. A motor 25rotates the pinion 26.

It can be seen that the dovetail coupling 13 tapers downwards, whichprevents the element from dropping when it is released. A hole 27 ismade in the center or the bottom face 28 or the recessed dovetail side13. The hole 27 is used for the locking of the elements, which will bedescribed relative to FIGS. 7 and 8. The projecting side or the couplingcarries another hole 29 in which is located a locking bush 30 fixed tothe end or a finger 31 sliding axially within the elements 5, 6 or 7 ofthe track. In this connection it is pointed out that the elements 5, 6and 7 have, besides the slideways 9 and the rack 17, a profile locatedbelow them and whose function is to give the track the necessarymechanical strength and rigidity. It is therefore advantageously apolygonal or circular and hollow profile, i.e. it can contain a certainnumber of mechanisms, one of which is now being described. Stiffeningribs can partition the interior of the profile.

The cylindrical well of the profile of the elements 5, 6 and 7 isdesignated 32. It carries an inner tube 33 terminated in its part remotefrom the dovetail coupling 13 by a small cap 34 having a central opening35 through which passes the end of the finger 31. The inner tube 33supports a jacket 36 by means of two bearings 37 mounted in such a waythat the translation of the jacket 36 on the inner tube 33 is renderedimpossible. The jacket 36 carries a tap 38 in which is engaged athreaded boss 39 of the finger 31, as well as a wheel 40 having helicalteeth displaced by a pinion 41 having helical teeth. The pinion 41 ismounted on a vertical spindle extending into a compartment 42 projectinglaterally adjoining the wall 32. Two bearings 43 allow the spindle ofthe pinion 41 to freely rotate and said spindle projects beyond thelaterally projecting compartment 42 by a key end 44, which extendsslightly to the side of the rack 17 and the slideways 9 and slightlybelow the same.

The engagement of the key member 44 by a control mechanism located onthe vehicle 8 and which will be described hereinafter is responsible forthe rotation of the spindle of the pinion 41, the wheel 40 and thejacket 36, together with the translation of the finger 31 by theengagement of the threaded boss 39 in the tap 38. A key 45 engaged inthe central opening 35 and in the finger 31 prevents any rotationthereof. Finally, the bush 30 is introduced into the hole 27, which isconical like the end of the bush 30 in order to obtain a better centringand by means of which the slideways 9 are in precise extension of oneanother.

A description will now be given of the bent elements 6 more specificallyshown in FIGS. 9 to 11. They are rectangular or more generally have arandom shape. The rotation spindle 11 of the plate 10 is located at thetop and the ends of the sides are constituted by dovetail couplings 13.The plate 10 is significantly longer than the base of the rollers 14, sothat the vehicle 8 is exclusively engaged on the plate 10 when it isable to rotate it by actuating a control mechanism 50 laterallyprojecting over the plate 10 not far from the spindle 11. The controlmechanism 50 is also (FIG. 10) partly located beneath the plate 10 andin a cavity 51 made as a result of a break in the wall 32.

The control mechanism 50 firstly comprises an endless screw or worm 52rotating freely about a vertical spindle 53 and terminated upwards by aflat projecting key member 54. Two bearings rigidly maintain the spindle53 in a small box 55 integral with the plate 10. The small box 55 alsocontains a horizontally directed, oblique transmission shaft 56, whichrotates freely, while being held by other bearings in a fixed positionin the small box 55. The transmission shaft 56 is provided with a pinion57 displaced by the endless screw 52 and a secondary endless screw orworm 58 at its other end, which engages in a toothed wheel or ring 59having concave teeth in order to ensure a maximum size engagementsurface. The toothed ring 59 is screwed into the wall 32 and surroundsthe spindle 11. The rotation imposed on the secondary endless screw 58consequently produces forces on the small box 55 and therefore on theplate 10, which is made to rotate. The vehicle 8 controls rotations ofthe plate 10 until the portions of the slideways 9 which it carries formextensions of adjacent fixed slideways.

With reference to FIGS. 12 to 15 a more detailed description will now begiven of the inclination element 7. Their wall 32 is subdivided into twoparts 32a, 32b connected by screws 60, which compress a toothed ring 61between the parts, while maintaining them integral. The wall 32 alsocomprises a ring 32c, which surrounds the part 32b which issignificantly shorter than the other part and the end of the part 32aabout which they can rotate via a pair of bearings 62 on either side ofthe toothed ring 61. The bearings 62 are roughly located in the centerof the ring 32. The outer part 32c consequently carries the end of theslideways 9 in accordance with the requirement expressed in connectionwith the bent elements 6, i.e. that the length must exceed the base ofthe rollers 14, while still enabling the vehicle 8 to have access to acontrol mechanism 63 which, like the previously described controlmechanism, laterally projects to the side of the part 32c. This controlmechanism 63 also comprises a key member 64 alongside the slideways 9and the rack 17 and below the same, which controls an endless screw 65held by bearings 90 having an axially fixed position in the box 66 ofthe control mechanism 63. The endless screw 65 meshes with the toothedring 61, which is kept fixed by screws 60. The box 66 and the wall part32c integral therewith, which are consequently rotated about thebearings 62.

The dovetails 13 at the end faces of the parts 32a, 32b are oriented indifferent directions, which define the characteristic inclination angleof each element 7 and which is a right angle in the example shown inFIGS. 12 and 13.

It is pointed out that all the control key members for locking anddisplacing the mobile parts are of the same flat projection type. Theyare also located on the same side of the elements 5, 6, 7, whichoptionally makes it possible to control them by a common mechanism 100shown in FIG. 16 and which consists of a motor 67 driving a gear drive68 terminated by a vertical shaft 69, which is itself terminated by akey member 70 having a rectilinear notch or recess 71. The rectilinearprojections of the displacement and locking axes enter the notch 71 andit is then only necessary to stop the vehicle 8 in order that the motor67 can rotate the key members. However, the principle of such amechanism makes it necessary for the projections and notches 71 toalways be in extension so that engagement can take place and that thekey member 70 does not strike the flat projections, i.e. in the locallongitudinal direction of the track.

The motor 67 may only rotate the shaft 69 by an integral number ofhalf-turns. This requirement can easily be reconciled with that of aprecise positioning of the mobile parts, particularly due to theclearances provided in the transmissions. On returning to FIG. 15, itcan be seen that the part 32b is provided with two angular abutments 85,which limit the travel of the ring 32c by stopping a block 86 screwedthereto.

The key member 64 is extended by a spindle 87 to which it is rigidlyconnected. A sleeve 88 surrounds the spindle 87 and is connected to theendless screw 65 by a key 89. Two bearings 90 maintain the sleeve 88 inthe box 66. Moreover, two washers 91 are axially locked between the keymember 64 and the sleeve 88 by means of a joint 92 compressed betweenthe other end of the sleeve 88 and an elastic ring 93 inserted aroundthe spindle 87 opposite to the key member 64. It is also pointed outthat the key member 64, the washers 91 and the end face of the sleeve 88on which they bear have thickness changes, so that these parts slightlyoverlap one another and face one another by three pairs of stepped,longitudinal faces 94.

When the mechanical abutment is established, it is possible to rotatethe key member 70 until the rectilinear projection and notch 71 have thedesired longitudinal orientation, which is necessary for freeing the keymember 70 on advancing the vehicle 8. The rotation imposed on the keymember 70 is the reverse of that permitting the abutment and has anangle at the most equal to a half-turn. It brings about the separationof pairs of stepped faces 94, which have significant clearances, so thatno movement is now transmitted to the sleeve 88 and therefore to thering 32c, which remains in the desired position. The locking effectexerted by the joint 98 prevents as a result of the friction which itcauses any accidental rotation of the key member 64 until the vehicle 8returns (otherwise it would be locked due to the inability of clearingthe inclination element 7 on seizing the key member 64). The advantageof using an endless screw is that such a transmission mechanism isirreversible and consequently the ring 32c is maintained in place.

Similar, not shown mechanisms with frictional joints and stepped washersprovide an angular clearance for the key member and abutments definingstop positions exist for the locking systems of the elements 5, 8, 7 andthe control of the plates 10, their operation being the same.

However, the construction shown has another control mechanism 100'similar to the preceding one, although this duplication is notnecessary. It is located on the carriage 12 and shown in FIG. 5. It isresponsible for the locking of the elements 5, 6, 7, while the other isused for controlling mobile portions of the elements 6 and 7. A simplerdesign results from this. The second control mechanism 100' ispositioned in such a way that it grasps the key member 44 for lockingthe element held at the time when the latter is lowered with thecarriage 12.

For checking the correct angular position of the key member 70, the geardrive 68 comprises a shaft 101 above which projects a disk 102 havingrecesses 103 regularly distributed over its periphery and whose numberis such that each half-turn of the member 70 passes one of the recesses103 in front of a sensor 104. Moreover, the longitudinal orientation ofthe notch 71 is established when a recess 103 is in front of the sensor104.

The vehicle 8 is again shown in FIG. 17. It is possible to see levers 72for preventing the vehicle 8 from falling if it passes beyond the end ofthe track. There are sensors 73 (FIG. 4) able to detect marks 74 locatedon a generatrix of the walls 32 of the elements 5, 6, 7. Morespecifically, the marks 72 are located towards the end of each elementand it is possible to see a first mark 74a, which indicates to thevehicle 8 that it is necessary to slow down and a second mark 74bindicating stoppage. The marks 74 are identical and are constituted by asheet metal portion, which projects laterally from the wall 32. Marks ofother types such as reflecting points or other signs can also be used asa function of the nature of the sensors 73, i.e. optical, inductive,etc. It is obviously necessary to provide the control system for thevehicle 8, which is essentially of an electronic nature, with a memoryenabling it to count the already laid track elements and thus deducetherefrom the number of marks 74 which can be ignored, because they areno longer at the end of the track.

Similar marks exist for limiting the horizontal displacement of the railheld by the carriage 12. However, the lever 72 has been provided forpreventing the vehicle 8 dropping if the indications of the sensors 73were erroneous. As can be seen from FIGS. 18 to 20, the lever 72comprises a rod located below the chassis of the vehicle 8 pivotingabout a horizontal, transverse spindle 75 and provided with a step 76 atmid-length on its lower face and a castor 77 at its front end.

The castor 77 is located on a transversely curved end 78 of the lever72, so that it rolls on a planar track 79 of the support 80 of theslideways 9 and the rack 17. The support 80 is a uniform profile, whosesection is adapted to the specified functions and which is rigidlyconnected to the wall 32 by screws. It has a cavity 81 between thesupport portions of the slideways 9 which is partly closed by a low wall82 at the end of each track element 5, 6 or 7. When the castor 77reaches an open space after clearing the end of the track, the lever 72pivots downwardly about the spindle 75. However, the vehicle 8 continuesto move until its progression is interrupted by the lug 76 encounteringlow wall 82. It is then necessary to move back the vehicle 8. The track79 is terminated by a zone 83 having a significant gradient, which makesit possible to raise the lever 72 by allowing the castor 77 to rollupwards. Each element 5, 6 or 7 has a track 79, which starts with asimilar, but reverse gradient, so that the castor 77 only undergoes abrief lowering and then immediately rises as soon as it meets thefollowing element 5, 6 or 7. This arrangement must also be ensured atthe junction between the fixed and mobile parts of the bent andinclination elements 6, 7 respectively in order to prevent any initialincorrect positioning. A lever 72' similar to the lever 72 but locatedat the rear and symmetrically makes it possible to eliminate the samerisk during the return of the vehicle 8 if it has been forgotten tocorrectly actuate the mobile parts of the elements 6 and 7. If theinclination of the vehicle 8 can become such that the dropping of thelevers 72 or 72' is no longer ensured, they can be constrained by aslightly compressed spring, which forces them below the vehicle 8. Asimilar device is provided on the carriage 12 for preventing the heldelement from being excessively advanced thereon.

A lever 72" shown in FIGS. 5 and 17 is free to pivot between the pairsof rollers 18 in order to retain the held element if the latter hasexcessively advanced. The track elements have shapes such that they abutagainst the vehicle 8 if they are inadvertently pushed rearwards, unlessthe carriage 12 is lowered. An optical or inductive sensor 95 isprovided on the carriage 12 to stop the advance of the held elementunder normal, conditions, the lever 72" only fulfilling a safetyfunction. Another sensor can be added to stop the vertical movements ofthe carriage 12.

The different motors of the vehicle 8 are controlled by an electronicsystem positioned outside the enclosure 1 and supplied by an ordinaryelectric power supply. The connections are constituted by electricalwires pulled by the vehicle, which causes no special problem providedthat the track is not excessively long or complicated as regards shape.The wire system is designated 97 in FIG. 1 end the electronic system 98.It would be possible to control the motors by radiowaves and to supplythem by a battery positioned on the vehicle 8, or to have electricityconducting tracks, on which would rub collecting brushes located on thevehicle 8. Such tracks could be positioned close to the slideways 9. Inconnection with the elements 6 and 7 having mobile parts, it isnecessary to establish a permanent bypass connection between the twoelements which they would join and which would continuously supply thetrack fragment located on the mobile part, no matter what the positionthereof, unless a rechargeable battery was provided on the vehicle 8.

The track must have an overhang section of approximately 6 meters andcarry a load of 50 kg in the existing construction. Although thissolution would not be suitable for numerous applications, it could beincreased by the use of bifurcation bent elements 106 (FIG. 21)generally similar to the already described bent elements 6, but whichwould also have a direction change end 107 (e.g. at right angles) and amain track end 108 (e.g. in the extension of the already installed trackpart). A dead-end track 109 used as a support means would then be laidas from the direction change end 107 and would then overhang a bracket110, which would serve as a support point or between the jaws of a vicewhich would then ensure a fourth take-up fixing on closing. The supportwould then be relieved.

When the intervention zone is reached, the laying vehicle 8 is withdrawnand replaced by another one, which carries the desired tool, but whichis similar to the previously described vehicle, because it has meansnecessary for attachment to the slideways 9 and for moving along thetrack while moving the mobile parts thereof. These are mainlyconstituted by the carriage 12 and the ancillary, omitted mechanisms. Astandard task in this field of activity is the changing of a pipesection, the tools then being used for dismantling or cutting and thenfitting or welding the new section.

The dismantling of the track causes no realization or understandingproblems, because it is performed by the operations which are thereverse of those already described.

We claim:
 1. A track and a vehicle, said track being comprised of trackelements and said vehicle being operable to lay said track elements andbeing guided and advanced on said track, said vehicle comprising achassis provided with guiding and advancing means engaged on said trackelements and a carriage for transporting a carried track element andpositioning said carried track element at a free end of said track so asto interlock said carried track element with said track, each of saidtrack elements having front and rear ends and a rail system, said trackelements being joined at said front and rear ends such that said railsystem extends generally continuously along said track, said front andrear ends of said track elements providing faces defining substantiallycomplimentary, vertically abutting, sliding couplings for interlockingengagement of the track elements, said rail system being engagable withsaid guiding and advancing means to guide said vehicle along said trackelements, said track elements being engagable with said guiding andadvancing means to advance said vehicle along the track elements.
 2. Thetrack and vehicle according to claim 1, wherein the sliding couplingscomprise tapered dovetails.
 3. The track and vehicle according to claim2, wherein said track elements comprise a locking device having a recesson the face of one of said front and rear ends and a part (31) mobileunder the action of a control mechanism on the face of the other of saidfront and rear ends.
 4. The track and vehicle according to claim 1,wherein said track elements (5, 6, 7) provide a stop mark (74b) to bedetected by a vehicle sensor (73) for detecting the free end of saidtrack.
 5. The track and vehicle according to claim 4, wherein said trackelements provide a slowing down mark (74a) axially aligned with the stopmark.
 6. The track and vehicle according to claim 1, wherein said trackelements comprise a body having a central groove (81) terminated by anabutment a 11 (82) generally near one of said front and rear ends. 7.The track and vehicle according to claim 1, wherein said track compriseselements for changing the direction of the track.
 8. The track andvehicle according to claim 7, wherein said direction changing elementscomprise branched elements (106).
 9. The track and vehicle according toclaim 7, wherein said direction changing elements comprise bent elements(6).
 10. The track and vehicle according to claim 7, wherein saiddirection changing elements comprise elements for changing theinclination of the vehicle.
 11. The track and vehicle according to claim10, wherein said inclination changing elements comprise two parts inextension, said parts each comprising one of said front and rear endsand being linked by a mechanism operable for rotating at least a portionof said rail system of said inclination changing elements about an axisjoining said front and rear ends.
 12. The track and vehicle according toclaim 7, wherein said direction changing elements comprise parts (10,32c) which rotate under the action of a control mechanism.
 13. The trackand vehicle according to claim 3, wherein said control mechanismcomprises an endless screw irreversible gear.
 14. The track and vehicleaccording to claim 13, wherein said locking device comprises mechanicalabutments.
 15. The track and vehicle according to claim 14, wherein saidcontrol mechanism comprises a spindle terminated by a flat projectionkey member.
 16. The track and vehicle according to claim 15, whereinsaid spindle has an angular clearance for orienting said flat projectionkey member parallel to said track elements and is held against rotationby friction.
 17. The track and vehicle according to claim 8, whereinsaid branched elements have front and rear ends and a mechanism operablefor rotating at least a portion of said rail system of the branchedelements about an axis perpendicular to a line joining the front andrear ends of said branched elements.
 18. The track and vehicle accordingto claim 9, wherein said bent elements front and rear ends and amechanism operable for rotating at least a portion of said rail systemof the bent elements about an axis perpendicular to a line joining thefront and rear ends of said bent elements.
 19. The track and vehicleaccording to claim 12, wherein said parts which rotate comprisemechanical abutments.
 20. The track and vehicle according to claim 19,wherein said control mechanism comprises a spindle terminated by a flatprojection key member.
 21. The track and vehicle according to claim 20,wherein said spindle has an angular clearance for orienting said flatprojection key member parallel to said track elements and is heldagainst rotation by friction.
 22. The track and vehicle according toclaim 1, wherein each of said track elements have a rack parallel tosaid rail system, said rack being engagable with a motive pinion of saidguiding and advancing means to advance said vehicle along the trackelements.